Extraction thimble



Sept. 4, 1945. R, ARNOLD EXTRAGTION THIMBLE Filed March 20, 1945 Ale/Vii) 1Q- A/il Ola INVENTOR.

nrom'iy Patented Sept. 4, 1945 UNITED STATES PATENT OFFICE EXTRACTION 'rm'MBLE Melvin R. Arnold, Charlestown, lnd assignor to E. I. du Pont de Nemou ton, Del., a corporatio rs & Company, Wilmingn of Delaware Application March 20, 1943, Serial No. 479,952

. 2 Claims. This invention relates to extraction and more particularly to an improved extraction thimble and method of extraction, which has special application in the ether extraction of colloided ni-' smokeless powder, and for extractor operates eilisubstances containing after, together with a preferred embodiment illustrated in detail in the which- Fig. 1 is a horizontal view of an extraction thimble embodying the present invention, and

Fig, 2 is a cross-sectional view takenon line A-A of Fig. 1. Fig. 3 is a cross-sectional view of the improved extraction thimble shown in operative position in a Knorr'type apparatus.

Fig. 1 shows the main body It of the thimble with the hollow arm I! communicating with the well of the thimble at thepoint designated II. It will be noted that a particular feature of the accompanying drawing in hollow arm resides in the fact that it terminates at a level substantially below the lip of the thimble so as to in the thimble at all times during the ether extraction of the sample for analysis contained in the thimble.

The extraction apparatus shown in Fig. 3 comprises the conventional form of Knorr flash' l5, having a cylindrical mouth portion or skirt l6, which with the exterior circumferential portion i1 forms a trough or mercury well n. Seated in this trough is the lower end of an extraction v tube is adapted to receive the extraction thimble III in its upright operating position. The extraction thimble is supported in position in the extraction tube by means of the skirt portion i6 of the flask upon which it rests. The extraction thimble is shown as containing the powder sample I 3 having a. wadding of cotton or like material at the top and bottom ofthe sample to maintain the particles of powder in the thimble during extraction.

The upper portion of the extraction tube forms maintain constant level of the ether in which the solubility a full column of liquid a vapor chamber communicating with the condensing tube 2| which is surrounded by the condenser shell or cooling jacket 22.

As will be noted from the illustration in Fig. 3,

during extraction so as to maintain a constant level of other over the sample of powder in the thimble while the vapors from the heated flask I! move upwardly through the extraction tube I i.

To accomplish the best results it is preferable that the sample of smokeless powder or other form of nitrocellulose intended for analysis be comminuted, especially if the grains or particles-are V of substantial size.

Compared with the straight type thimble re. quiring 48 hours extraction time for the extraction of ether soluble material from a sample of smokeless powder, the extraction time can be completed in 24 hours by means of my new and improved thimble, and in most cases this time .can be reduced to within 18 to 20 hours. This reduced period of extraction time is made possible by the fact that the colloided material is maintained completely immersed in ether held in the thimble throughout the entire extraction period.

' This reduced time of extraction is an important desideratum in the control of manufacture of smokeless powder or'other forms of colloided nitrocellulose in large scale production. V

The foregoing is given by wayof illustration of a specific embodiment of my invention and is not to be taken in any manner as a limitation of the invention.

It will be apparent from the foregoing detailed description that this improved extraction thimble and method of extraction will be found useful not only in the analyses of smokeless powder samples, but may also be used in determining the total soluble extract'in other materials containing extractable matter. preferable for extracting soluble material from smokeless powder, this improved thimble may be used equally well with other solvents. I

Apart from accomplishing itspurpose in giving greatly improved results over the well-known Soxhlet extractor, it is free from the undesirable properties of fragility and high cost found in such prior known devices. My new and improved, thimble is adapted to be and preferably is used with the KnOrr type of condenser and flask.

I claim:

1. An extraction apparatus comprising in com- I bination a flask having a mouth portion, 8.! exaction tube surmounting the flask and having is maintained in the side .arm ll of the extraction thimble at all times While ether is considered a. vapor chamber in its upper portion, a condensportion of the flask and having a vapor chamber ing tube in communication with the vapor chamformed in its upper portion, an extraction thimble her, an extraction thimble supported within the supported within the extraction ,tube with its upextraction tube with its upper ortion in comper portion in communication with the vapor munication with the vapor chamber, said ex- 5 chamber, a condensing tube in communication traction thimble comprising a well to receive a with the vapor chamber, said extraction thimble sample of material to be extracted and open at comprising a well to receive a sample of material the top to receive solvent from the vapor chamto be extractedand open at the top to receive a her, and a hollow side arm in communication at solvent, and a hollow side arm in communication its lower end with the bottom of the well but 10 with the bottom of the 'well and extending in having a length less than the length of the thimsubstantially parallel relation with the well but ble and open at the top to serve as a discharge terminating at a level slightly below the upper ior the solvent while maintaining a constant level end or the-thimble and open at the top to serve oi the solvent in the thimble throughout the exv as a discharge for the solvent to maintain a contraction period. 4 15 stant level of the solvent in the thimble through- 2. An extraction apparatus comprising in comout the extraction period.

bination a flask having a mouth portion, an extraction tube in communication with the mouth MELVIN R. ARNOLD. 

